Epoxy resin compositions are used in the manufacturing of various articles, including composites. For certain types of composites, especially for aerospace uses, it is desirable to increase the modulus of the resin matrix in order to improve various properties of the composite. Substitution of highly functional glycidylamine resins for conventional bisphenol A-based epoxy resins in a given formulation may increase modulus but generally at the cost of a considerable reduction in fracture toughness. A resin or curing agent which may give increased resin matrix modulus (in comparison with similar systems using standard bisphenol A-based epoxy resins), with less loss of elongation or toughness (as measured by quasistatic fracture toughness, fatigue crack growth resistance, etc.) would be highly desirable for some applications. Also, resin systems of reduced viscosity are desirable for many fabrication techniques such as filament winding, resin transfer molding, infusion or prepregging.
In light of the above, there is a need in the art for epoxy resin compositions and curing agents for composites with desired mechanical properties when compared to the prior art resin compositions.